To continue with the open source practice, the founders of
MySQL Michael Widenius, David Axmark, and Allan Larsson last year announced a
new database, MariaDB that is an enhanced, drop-in replacement of MySQL.

If you do not like Oracle or let's just say, if you do not
trust Oracle, MariaDB is the way to go. It is very similar to MySQL and there
is not much learning curve. If you are an existing MySQL developer or DBA, you
will find yourself home with MariaDB.

From the MariaDB website, here is the definition:

MariaDB is the compatible successor to MySQL, the world's
most popular Open Source database. MariaDB has greatly improved scalability and
performance, engines for NoSQL and volume transaction processing, and
clustering capability. The MariaDB client libraries are available under the
liberal LGPL license, enabling a new generation of commercial applications. In
a study by the 451 Group in May 2012, 85% of the companies surveyed were using
MariaDB or MySQL data formats.